1/12/2024 0 Comments Weather radar![]() To remove these unwanted reflections a filter is applied but it may also remove reflections from rain in the same area if these rain reflections are weaker than the ground clutter reflections. This results from the radio energy that is reflected back to the radar from these targets. It is only if the cloud stops completely over one area that all the 30mm fall into that area.Ĭoloumn Max: A display, in plan, of the maximum value of the reflectivity above each point at different altitudes of the area being observed, consequently, it is the maximum of PPIs (Plan Position Indicator) in the individual point.īuildings and hills in the vicinity of the radar produce what is known as “ground clutter” on the radar image which is highlighted by a dotted circle. One has to bear in mind that clouds move and this means that in one hour 30 mm of precipitation is spread over a very large area. ![]() The bright red means that rain is falling at the rate of 100 mm per hour, and the darkest blue means that the rain is falling at the rate of 0.1mm per hour. On the right hand side, underneath the date and time – which is in UTC (known also as GMT) and which is one hour behind Malta Winter Time, and two hours behind Malta Summer Time, one finds a table showing the rate of rainfall. This particular radar image shows the rate of rainfall in millimetres per hour of the ‘echoes’ produced. In short the display produced by the radar’s computer gives a horizontal map of where rain is falling and an estimate of how heavily it is falling. The “reflecting power” of the rainfall (which depends on the size of the raindrops and their concentration) is also calculated, thus providing an estimate of rainfall intensity unit used is the dBz. The radar’s computer determines the direction of the rain from the azimuth (orientation) of the antenna, and the distance to the rain from the time taken for the radar signal to return to the receiver. In RADAR (Radio Detection and Ranging), radio pulses are transmitted, in a highly focused beam, by a radar antenna and are reflected off objects and returned to a receiver at the antenna.
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